News
-
Health & MedicineEstrogen Safety: Studies raise cancer, blood clot questions
Two studies provide conflicting findings on estrogen therapy's effect on breast cancer risk, while a third study suggests that the hormone contributes to blood clot formation.
By Nathan Seppa -
Health & MedicineMicrobe Hunt: Novel bacterium infects immune-deficient people
A newfound bacterium can cause illness in people who have a rare, inherited form of immune deficiency.
By Ben Harder -
AnthropologyBranchless Evolution: Fossils point to single hominid root
Fossils of a 4.1-million-year-old human ancestor in Ethiopia bolster the controversial idea that early members of our evolutionary family arose one species at a time rather than branching out into numerous species.